Research Reports - The impact of preexisting illness and substance use on functional and neuropsychological outcomes following traumatic brain injury

Traumatic brain injury (TBI) is a significant public health problem in the US.
Specific preexisting medical illnesses delay recovery after TBI and increase
mortality or risk of repeat TBI. This study examined the impact of preexisting
illness and substance use on patient rehabilitation outcomes following TBI. The
Functional Independence Measure total score and Disability Rating Scale score
measured functional outcomes at discharge from inpatient rehabilitation, while
the Trail Making Test A and B and Total Trials 1-5 of the California Verbal
Learning Test-II measured neuropsychological outcomes in 128 TBI survivors with
moderate or severe TBI. Results showed that the presence of a heart condition or
diabetes/high blood sugar was associated with lower functional outcomes by
discharge. A history of a heart condition, stroke, or respiratory condition prior
to TBI was associated with reduced cognitive flexibility. Those with preexisting
diabetes/high blood sugar demonstrated poorer visual attention, visuomotor
processing speed, and ability to learn and recall verbal information. Those with
pre-TBI cancer also had greater auditory-verbal memory deficits. The findings
showed that specific preexisting medical conditions are independently associated
with lower functional and cognitive outcomes for patients with TBI. By screening
patients for preexisting medical conditions, multidisciplinary TBI rehabilitation
teams can identify patients who require more aggressive treatments or greater
length of stay.